People who wonder if they’ve been sick with the coronavirus can now be tested for COVID-19 antibodies at urgent care clinics throughout the St. Louis region. The results could show if someone was sick with the illness and recovered.
Antibodies are proteins the immune system makes to fight sickness. Having them means a person has been exposed to the virus.
But doctors caution they still know little about what the results of COVID-19 antibodies tests reveal.
“I think one of the challenges with this test is we really need to get to the bottom of what it means to be positive,” said Dr. Alex Garza, the head of the St. Louis Metropolitan Pandemic Task Force. “We don’t know what it means. All it means is you have antibodies.”
The antibody tests offered at clinics don't reveal if people have COVID-19. They only show only if they had it in the past.
Scientists say that, with some diseases, the presence of antibodies provides the person with immunity. But there’s not yet concrete evidence that’s the case for COVID-19, said Dr. Neil Anderson, Barnes-Jewish Hospital clinical microbiologist.
“We don’t know if having detected antibodies means you’re actually immune to the virus,” he said. “I think there has been a lot of hype in the lay press and even from a government level about the utility of these antibodies tests, but at this point we’re still struggling with how to interpret these results.”
Even if it turns out people with the antibodies are immune, there’s no proof of how long that immunity would last, he said.
Companies could request their workers be tested before they go back to work, said Dr. Sonny Saggar, owner of 24/7 Healthcare urgent care centers in Creve Coeur and downtown St. Louis.
But mostly, patients are curious about whether they have had the disease.
“I think most of these people want to know, that’s the biggest category,” Saggar said. “That seems to be the No. 1 reason.”
The clinics Saggar runs have tested more than 250 people since they began offering the test last week, he said.
At 24/7 Urgent Care, when a patient wants an antibody test, a health worker takes a blood draw and sends it to an off-site lab, where it is tested for antibodies, Saggar said. Results typically come back within a few days.
“There’s definitely disappointment when it comes back negative,” Saggar said. “It’s the opposite of some other blood tests.”
Total Access Urgent Care has tested more than 4,000 people for coronavirus antibodies in recent weeks, said Dr. Matt Bruckel, its founder and chief executive officer.
“I think a large degree of this pandemic has been based on fear,” he said. “There’s the fear of the virus, the fear of getting infected, the fear of dying that’s driven people underground. ... People are looking for some reassurance and some information in order to make decisions.”
For most people, insurance pays for the test at both Total Access and 24/7, the two doctors said.
Those who test positive for the antibodies still need to be careful, Saggar said.
“There is a worry that if you come back positive, you’re going to start walking around without a mask — and you’ll stop washing your hands — and hugging and kissing people,” he said.
Misinterpreting what the tests mean could be dangerous, Anderson said.
“I think a lot of people are looking at these as sort of a peace of mind, but it can potentially cause more confusion than good,” he said. “I would urge healthy skepticism for anyone who wants to be tested.”
Not all tests that have been introduced in recent months are proven to be accurate, said Anderson, the microbiologist.
The Food and Drug Administration in March allowed manufacturers to flood the market with tests that were vetted for accuracy by the manufacturers, not by federal regulators, Garza said. The FDA has since begun to regulate which tests labs are able to use.
The best way to ensure accurate results is to receive the tests through a medical provider that uses a professional lab and not a mail-order test sold on websites, Anderson said. Such labs independently certify the efficacy of any tests they conduct.
But the tests can be useful even if they don’t prove immunity to consumers, Anderson said.
For example, some people who have recovered from COVID-19 and have tested positive for antibodies are eligible to donate blood to sick coronavirus patients through convalescent plasma programs. The programs transfuse blood from recovered patients to patients sick with the coronavirus to see if it could help them fight the disease.
Public health officials can also use antibody tests to see who and how many people became sick with COVID-19 in different communities.
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